Engineered Natural Stone Retaining Wall

I need an engineered design plan for a natural stone retaining wall in Connecticut, over 3 feet tall, with an engineer's stamp. I started to extend the existing wall 10 feet to meet the stairs that need to be replaced from the road. I have pictures of every step but town requires a stamped engineer plan. I would like to raise the existing wall as well.

Key Requirements:
- Retaining wall function
- Natural stone material
- Engineer's design and stamp

Ideal Skills and Experience:
- Civil or structural engineering
- Experience with retaining wall design
- Knowledge of local CT building codes and regulations

Please provide relevant experience and estimated timelines.